Conventional lenses are typically formed of a number of varying thickness pieces of glass or plastic to make lenses, where the glass or plastic has a particular index of refraction.
The recent development of Transformation Optics (TO) provides a new way of looking at the independent control of the electrical and magnetic components of electromagnetic fields [see Pendry, J. B., Schurig, D. & Smith, D. R., (2006) ‘Controlling electromagnetic fields’, Science, 312, pp. 1780-1782]. TO is enabled in practice through the use of metamaterials. As disclosed in Pendry et al. “ . . . metamaterials owe their properties to their sub-wavelength material-structure rather than to their chemical composition, and can be designed to have properties impossible to find in nature.”
At the sub-wavelength level, light breaks up into its component electrical and magnetic fields, and the concept of a ray of light is meaningless. In this case, TO replaces Snell's Law of Refraction. TO is the valid mathematics at the sub-wavelength scale.
U.S. patent application Ser. No. 13/438,433, entitled “HIGH REFRACTIVE INDEX, POLARIZATION INSENSITIVE NANO-ROD BASED PLASMONIC METAMATERIALS FOR LENSES”, filed on Apr. 3, 2012, which is incorporated by reference in its entirety herein, discloses the use of plasmonic metamaterials as a high index of refraction optical material, where the optical material may be used for lenses, such as Graded Index (GRIN) lenses.